Australia and Israel also have plenty of sun, and problems with fresh-water supplies, and even those countries don’t deploy much solar. Australia does, however, use renewable wind energy projects to run reverse-osmosis desalinization plants, which is an ideal use for such infrastructure, because you can literally store the energy-intensive products of the irregularly-supplied power-source in tanks, for later on-demand use, like a battery-equivalent. Meanwhile, fossil plants provide good base-load and peak electricity supply for ordinary industrial and individual consumers.

Saudi Arabia also has vast expanses of open desert seemingly tailor-made for solar-panel arrays.

My understanding was that sandy desert was less than ideal for solar deployment due to panel erosion and the like?